DE2436195A1 - IMPROVED CORD FABRICS AND THEIR USE, ESPECIALLY IN AIR TIRES - Google Patents

Description

PATENT LAWYERS

MANITZ, FINSTERWALD & GRÄMKOW

Munich, July 26th 1974 P / Sv-D 2050

DIMIOP LIMITED
Dunlop House, Ryder Street, St James's, London SW1 England

Improved cord fabrics and their uses, especially at

tire

The invention relates to cord fabrics and in particular to outer fabrics, which are suitable for use in reinforcing articles made of rubber, such as pneumatic tires.

According to the invention comprises a weft yarn for use in cord fabric at least one yarn consisting of a mixture of polyester fibers and rayon staple fibers.

According to a further embodiment of the invention, an outer fabric comprises warp cords and weft yarns, the weft yarns in each case comprise at least one yarn made from a mixture of polyester staple fibers and rayon staple fibers.

DR. G. MANITZ · DIPL.-ING. M. FINSTERWALD DIPL. -ING. W. GRÄMKOW ZENTRALKASSE BAYER. FOLK BANKS

β MÖNCHEN 22. ROBE RT-KOCH-STR ASSE I 7 STUTTGART 50 (BAD CANNSTATT) MÖNCHEN. ACCOUNT NUMBER 72

TEL. (089) 22 42 II. TELEX 05 - 29672 PATMF SEELBERGSTR. 23/25. TEL. (0711) 56 72 61 POSTSCHECK: MÖNCHEN 77062 - 80S

409886/1419

According to another embodiment of the invention, a pneumatic tire comprises a tread section, two sidewall sections, connecting the two bead areas to the tread portion, and a carcass reinforcement, the reinforcement at least includes a reinforcing layer of gord fabric as previously defined

The weft yarns can contain between 80 # to 20 % polyester and between 20 # to 80 % rayon, but are preferably composed of 67 # polyester and 33 # rayon. Generally, each weft is a single yarn, although more than one yarn is also used can.

The warp cords used in the fabric can be any conventional one Cords that are suitable for use in tire cord fabric, e.g. cords made of rayon, nylon, polyester, glass fibers, aromatic polyamide or steel.

Weft yarns are used to control the spacing of the warp cords and hence the width in the tire cord fabric. the Weft yarns must exert this control over a wide range of conditions that the fabric will encounter during Processing that precedes tire building is subject to. Many weft materials are used during this processing inadequate. Two weft materials currently used in tire cord fabrics are 30s (in the cotton numbering system) Cotton and Durafil rayon (Durafil = »description of goods). Under the processing conditions, cotton tends to have inadequate properties, whereas Durafil rayon is satisfactory provided that hard mechanical processing of the shot, e.g. guiding it over sharp edges, and high temperatures are avoided. If temperatures above 235 ° 0 are used during tissue processing, heavier, stronger weft yarns must be used.

409886/1419

The object of the invention is to create better weft yarns Quality with high uniformity of properties under processing conditions.

This object is achieved by the weft yarn according to the invention. The invention is explained in more detail by means of the following examples

Example. 1

A number of weft yarns, which comprised 30s single yarns made from staple fibers, were examined as explained below after they had been subjected to various processes, also described below. The staple fibers consisted of cotton (trade name Ike), rayon I (trade name Vincel), rayon II (trade name Durafil) and a mixture of polyester / rayon I in a ratio of 67 # polyester to 33 % rayon fibers.

Process 1

The yarns were "conditioned" by being relaxed 24 hours in a standard laboratory atmosphere of 65% relative humidity at 21 ⁰ G. This process simulates the weaving of the Oordewebbe.

Process 2

The yarns were oven-dried for 1 hour at 107 ⁰ C in an oven with a free circulation of air, and then tested immediately in the standard laboratory atmosphere.

This process simulates the hot bonding of the ortic tissue.

Process 3

The yarns were soaked for 15 min in water containing a small amount of wetting agent contained, relaxed, and were immediately placed in the standard laboratory atmosphere examined.

This process simulates the preparation (finishing).

409886 / U19

Process 4

The Garn® was immersed in an RPL adhesive, 1 min at 170 ⁰ O and dried for 1 min at 180 to 230 ° 0 ⁰ O heat treated.

The yarns were then re-submitted to Process 2 prior to testing.

This process simulates hot stretching after preparation.

The yarns have all been "conditioned" and then one of the processes 2 to 4 before the examination.

The tensile strength and elongation at breakage of the yarn after each one the processes 1 through 4 were determined by taking a length of 50 cm Yarn was tested on an Instron CRE tensometer at a speed of 30 cm / min. The investigations were carried out on yarn repeated by looping an overhand knot in Center of the test piece according to the ASTM (D2256) -24 standard immediately after being subjected to process 1 to 4, knotted had been.

In addition, lengths of around 24 cm of the yarns were tested for shrinkage under the following conditions »

Wet The "conditioned" yarns were soaked in water

immersed to make them completely full aspirated, and the change in length between the wet yarn and the "conditioned ¹¹ yarn was determined ·

let dry »The wet yarn was then in an oven at 150 ⁰ O

dried for about 5 min. The change in length between the dried yarn and the wet yarn were determined.

These two stages simulate the preparation process and the drying process that the tire fabric takes is subjected.

Thermally “conditioned” yarns were at 150 ⁰ O for 1 min

dried, and the difference in length between

403886/1419

see the dried yarn and the "conditioned" Yarn determined.

This stage simulates the drying temperature, which after the preparation / or some other High temperature process on the fabric.

The results of these studies are shown in Table I below compiled:

TABELUE I

Yarn cotton
(Ike) 17.8 Rayon I
(Vincel) Rayon II
(Durafil) Polyester/
Rayon I tex (process 2) 7.4 18.1 17.2 17.9 # Humid
purchase
took 13.5 12.1 4.4 Tear resistance
(g / tex) 17.4 Process 1 12.9 19.3 20.9 25.7 Process 2 20.8 26.5 23.8 24.6 Process 3 18.5 14.9 14.5 25.1 Process 4 32.0 32.0 27.4 Tear resistance
(g / tex) for ver
knotted yarn 17.4 Process 1 12.9 17.7 18.6 23.5 Process 2 20.8 23.8 22.7 25.7 Process 3 18.0 14.4 14.5 25.7 Process 4 22.7 22.1 24.0 Extensibility (#) 6.0 Process 1 3.5 9.2 16.6 10.2 Process 2 9.3 7.3 11.8 9.8 Process 3 2.0 12.7 21.7 12.0 Process 4 2.4 3.6 4.5

4 U υ Η ύ B / 1 A 1 9

Continuation from TABLE I.

yarn

Cotton (ike)

Rayon I (Vincel)

Rayon II
(Durafil)

Polyester / rayon I

Extensibility for knotted yarn

Process 1 6.0 Process 2 3.1 Process 3 9.3 Process 4 2.1 Shrinkage (#) Wet 0.86 Wet dry 0.67 Thermal 0.5 ⁺ a increase in length Example 2

8.6, 6.2 11.8

1.6

-0.28 ⁺ 1.0

15.1
10.8

21.9
2.4

-O, 75 ⁺
-0.56 ⁺

9.5 9.6

11.9 4.2

0.29 0.67 1.9

A weft that is a single 20s thread of staple fibers from 67 # Polyester / 33 # Rayon I (Vincel) was tested after being treated as described in Example 1. Dia results are in the. compiled below in Table II.

TABKTiLK II # Moisture absorption Tear resistance
(g / tex) ) 0.20 28, 2 Stretchy
ability (#)
for ver
knotted
yarn tes- (process 2) 27.3 0.78 4, 14th 13.9 Process 1 23.7 1.4 AQv Tear resistance
(g / tex) for
knotted yarn Extensibility
(*) 1 ^! ., 2 Process 2 30.3 25.1 14.2 14.1 Process 3 27.8 22.3 13.4 7.2 Process 4 23.1 17.0 Shrinkage (^ l 24.2 8.5 Wet Wet dry Thfjrmijch > 8 8 6 / U 1 9

Example 3

For a weft yarn according to the invention made of, for example, 67 % polyester fibers and 33 # Rayon I fibers, the properties before treatment can typically be as follows:

tex 19t3 (nominally 20)

Breaking load (g) 376

Elongation at break. (#) 11.4

Tear strength (g / tex) 19.9

As already described above, cotton yarn is used for tire fabric has already been used. However, it has been found to be particularly inadequate when it became necessary to use the original Maintain the width of the fabric after processing, e.g. dissecting and stretching, as shoe cord breakage is common occurred under these conditions.

The Durafil-Rayon has at processing temperatures of 245 ° 0 or below was found to be satisfactory, but it was susceptible to mechanical damage. The shot material made of rayon I (Vincel) lies approximately in the middle between the weft materials made of cotton and Durafil rayon.

However, as can be seen from the results shown in Table I, the properties of the blend of polyester / Rayon is found to be surprisingly uniform over a wide range of conditions which set the processing conditions for tire fabrics simulated, exposed. These uniform properties give the advantage during the shaping process, the Radial substructures are carried out that the tendency to occur a random fracture instead of a Break in the manner of a zipper action in which the weft yarns are placed one at a time between two adjacent warp cords break altogether, occurs, this bruohart in cotton bottom yarns can easily occur. In this way, the distance the Oorde in the de »formed radial layer substructure improved will.

Claims (10)

Claims Weft yarn for use in outer fabrics, characterized in that it comprises at least one yarn consisting of consists of a mixture of polyester staple fibers and rayon staple fibers. 2. Weft yarn according to claim 1, characterized in that the yarn contains 80 # to 20 # polyester fibers and 20 # to 80 $ rayon fibers. 3. Weft yarn according to claim 1, characterized in that the yarn contains 67 % polyester fibers and 33 # rayon fibers. 4. Cord fabric comprising warp cords and weft yarns thereby characterized in that the weft yarns each have at least one yarn made from a mixture of polyester staple fibers and rayon staple fibers. 5. Cord fabric according to claim 4, characterized in that this yarn contains 80 # to 20 % polyester fibers and 20 % to 80 % rayon fibers. 6. Cordgdfebe according to claim 4 or 5 »characterized in that this yarn contains 67 % polyester fibers and 33 % rayon fibers. 7. Cord fabric according to claim 4, 5 or 6, characterized in that each weft yarn contains a single yarn. 8. Cord fabric according to one of claims 4 to 7 »characterized in that the warp cord is one of the following Materials contains: rayon, nylon, polyester, fiberglass, steel cords or cords made of aromatic polyamide. 409886 / U19 9. Pneumatic tire, which has a tread section, two sidewall sections, which connect two bead areas to the tread portion and comprises a carcass reinforcement, characterized in that the reinforcement is at least one reinforced layer of cord fabric according to a which includes claims 4 to 8. 10. Pneumatic tire according to claim 9 »characterized in that that the fabric layer is arranged so that the warp cords are arranged in radial planes of the tire. 4 09-8 86 / 1A1 θ